Automatic bagging machines



T. M. SHEETS AUTOMATIC BAGGING MACHINES Jan. 14, 1969 Sheet Filed Oct.19, 1966 Jan. 14, 1969 T. SHEETS AUTOMATIC BAGGING MACHINES Sheet 2 ofFiled Oct. 19, 1966 b m mm Jan. 14, 1969 T. M. SHEETS AUTOMATIC BAGGINGMACHINES Filed Oct. 19. 1966 I lllL United States Patent 5 ClaimsABSTRACT OF THE DISCLOSURE This invention relates to automatic baggingmachines which include clamping apparatus for clamping portions of thebag wall adjacent its mouth, and means for operating the clampingapparatus in timed relation to the other components of the machine.

This invention relates to automatic bagging machines and moreparticularly to machines of that class adapted for applying bags such aspolyethylene or other plastic film material to loaves of bread, othercomestibles or objects.

By way of example, the invention will be herein described andillustrated as applied to a so-called Mark 50 machine, now well known onthe market and as described and illustrated in the drawings of a manualpublished in March 1965 for that machine by Commodity Packaging Co.,Inc. of Yakima, Wash. (now Bakery Machinery Division, American Machine &Foundry Company, 2115 W. Laburnum Avenue, Richmond, Va. 23277). Featuresof the invention may be applied to other automatic bread packagingmachines of that class adapted for like or similar purposes.

In machines of that type, opposed spaced-apart scoop elements arereciprocatably mounted to travel endwise past an object such as a loafof bread and enter into the open mouth of a plastic film bag and becomespread apart to somewhat frictionally grip the bag internally, the scoopelements being then retracted for drawing the bag into the desiredposition surrounding the loaf. In order that the scoop element will thusadequately grip frictionally the interior of the bag mouth, it isnecessary in the existing machines of this class, that the scoopelements when spreading apart subject the film material of the bag toconsiderable tension. Also, if such frictional gripping is relied on,problems sometimes arise because of the varying slip characteristics ofthe film material which sometimes may become somewhat sticky or beardust-like material. Also the coeflicient of friction of the film againstthe scoop elements which may be of highly polished aluminum or stainlesssteel, will be such that the film is not properly frictionally engagedor released. The same difiiculty may arise when any foreign materialbecomes lodged on the scoop elements.

The present invention provides for certain improvements in the form ofreleasable clamping means mounted on at least one of the scoop elementsfor clamping the film material of the bag mouth securely in place on thescoop element at the proper times, thus providing positive means forhloding the bag in place on the scoops and avoiding the problems of theabove-noted variables. Also the present improvements make it possible toease the tension heretofore required on the film of the bag mouth.Either one, or preferably a pair of such clamping means may be providedon opposite sides of one of the scoop elements, for example the lowerscoop as hereinafter disclosed, and if desired, the other or upper scoopmay also be similarly equipped with such clamping means.

It may be mentioned that such plastic film bags, although intended to bemanufactured to predetermined 3,421,287 Patented Jan. 14, 1969 sizes,nevertheless are necessarily produced very rapidly and inexpensivelywith the film being heat-sealed with a so-called weld along one, orusually two longitudinal lines. In some cases such welds may be insecureand under these circumstances the circumference of the bag, althoughintended to be of a certain predetermined size, may vary somewhat frombag to bag due to variations in the character and position of the linesof heat-sealing or due to variations in the stretchability of the filmmaterial under varying conditions. As a result the scoop elements whichenter the bag mouth and shape same to receive the load, may from bag tobag tend to exert different amounts of pressure against the interiorsurfaces of the bag walls. Thus even though the operating supports forthe two scoop elements may be carefully adjusted so that they willexpand in the bag to accurately predetermined spacedapart positions foraccommodating a predetermined size of bag, yet, because of thevariations in the successive bags, the scoop elements may in some casesoverstretch the mouths of the bags or disrupt the welds, or in othercases fit in place too loosely, and cause disruption of the film of thebag or allow it to slip out of proper control. Even if this occurs onlyinfrequently or if the bags slip out of place only infrequently, it willbe necessary to stop the machine for a considerable period to clean awaydisrupted bags and possibly mangled bread loaves or other commodities,and also this will interrupt the regular normal automatic flow throughthe plant of the commodity being made and bagged.

In accordance with the present invention, the clamping means grips thefilm at the bag mouth and clamps same against one of the scoop elements,such as the bottom scoop on its forward stroke after it has entered thebag sufiiciently to hold the bag mouth open. Usually with theabove-mentioned class of machines, the plastic film bags are positionedas a stack of same in flattened con dition and held on suitable wicketmeans. Air pressure is used to blow open the mouth of the top bag of thestack to enable the scoops to enter. The clamping means provided by thepresent invention in effect supplements the frictional engagement of thescoops within the bag mouth, to the extent required more easily to stripthe bag off the wicket means. As the scoops separate to maximum spacingtherebetween inside the bag mouth, preferably the clamping means isarranged to release the film momentarily to permit any slack film whichmay be trapped under the bottom scoop between the clamping means to bestraightened out, whereupon the scoops as they separate are permitted toopen the bag mouth to the maximum desired extent for a given size ofbag. Then the clamping means is arranged again to become closed to clampthe film against the scoop means, this occurring just as or shortlyafter the scoop means has begun to travel on its working stroke toretract the bag and draw it over the object being packaged.

The clamping means further in accordance with the invention, serves toclamp each bag in position on the scoops until they have been retractedto a predetermined position so that the bag may be released by theclamps at an adjustable predetermined time after the object being baggedhas been fully enclosed by the bag.

In such machines a blockade device is provided against which the object,such as a bread loaf, is adapted to come into engagement to prevent itslongitudinal movement as the bag surrounding same is drawn firmly intoplace thereon. Since the clamping means of the present invention can beadjusted to become released at an accurately predetermined time, thepressure between the loaf or other object and the blockade will bereduced when the clamping means releases and so that the frictionalresistance of the scoops upon finally sliding out of the bag mouth, doesnot have to be great enough to draw the object or loaf with any unduepressure against the blockade, or to cause any troublesome impactthereon, or betweeen the end of the object or loaf and the gussetformation usually provided at the bottom end of such plastic film bags.Thus in short the clamping means provides a positive expedient forholding the bag on the scoop elements without relying on frictionalresistance or any excessive tensioning of the film by the scoops.

In a co-pending US. patent application of Edward J. Chambless, Jr., Ser.No. 570,584, filed Aug. 5, 1966, another expedient is disclosed andclaimed for minimizing certain of the problems occurring with the classof machine here involved. That is, as disclosed in said application, oneof said scoop elements, for example the upper one, is associated throughsuitable linkage with means in the form of an air operated cylinder andpiston device for so applying pressure to the linkage as to urge suchupper scoop element with a uniform pressure against the upper inner wallof the mouth of the bag. The pressure which the scoop element is thuscaused to exert will be uniform, even though the upward movement of thescoop element in coming into engagement within the inner wall of themouth of the bag, will be stopped at varying levels depending oninaccuracies in the dimensions or character of successive bags. For bestresults the expedient disclosed in said Chambless application mayconveniently be used in combination with the present invention, althoughthe present invention, has b een found to give strikingly successfulresults without such expedient, and particularly in the case of filmbags which may have weak side seams so that it is difiicult to pull suchbags from the retaining wicket without undue strain on the side seams.

Various further and more specific objects, features and advantages ofthe invention will appear from the description given below, taken inconnection with the accompanying drawings, illustrating by way ofexample a preferred form of the invention.

In the drawings:

FIG. 1 is a side elevational view of the machine of the particular typeabove referred to and embodying the improvements of the presentinvention;

FIG. 2 is an enlarged elevational view of the parts of such a machine;

FIG. 3 is a plan view of the arrangement of certain of the parts moreparticularly concerned with the improvement of the present invention;and

FIGS. 4 and 5 are perspective views showing the operation of the scoopelements and clamping means in accordance with the inventionrespectively just as same are about to enter the open mouth of a bag andjust as same are about to retract to draw the bag onto the object beingpacked.

The essenial parts of the above-mentioned type of machine will first bereferred to and including also the improvement of said Chamblessapplication, although the latter forms no part of the present inventionexcept to the extent that same may optionally be used in cooperativecombination with the present invention to achieve best results. Suitableconveyor means, although not shown in FIG. 1, may extend generallyhorizontally from the position of the viewer transversely across the topof the machine as shown in FIG. 1, to convey loaves of bread or otherobjects to a packaging station at the position indicated at 10.Equipment indicated generally at -11, of any suitable known type, may beprovided for holding a stack of the initially flat plastic film bagswhich are brought into a position so that as by the use of air jets, themouth portion of each successive bag is blown to an open condition readyto receive spaced-apart upper and lower scoop elements as at 12, 13which are reciprocated endwise past the loaf of bread, for example,located at 10, to enter into the open mouth of a plastic bag which hasbeen made ready to receive same by the equipment at 11. Meanwhile aso-called blockade arrangement indicated generally at 14 is operated tothrust a blocking element 15 into contact with the end of the loaf toretain same again endwise movement at the packaging station 10 while thescoop elements 12 and 13 have entered into and engaged within the mouthof the plastic bag. Then the scoop elements are retracted to pull thebag over the loaf at station 10, while the loaf is prevented from movingby the blockade device until the plastic bag is drawn into positionfully to contain the loaf, and the scoop elements are retracted to theposition shown in FIG. 1.

The scoop elements are carried by a shuttle element indicated at 16which reciprocates along a shaft 16a to move the scoop elements to andfro in the process of their reaching for a plastic film bag and drawingsame over the loaf. The shuttle element 16, as better shown in FIG. 2,may be operated by a link 17 pivotally connected at its upper end aboutan axis 18. The other end of this link is pivotally connected about anaxis 19 to a lever 20, which in turn is pivotally mounted about an axisas at 21 at the base of the machine. The lever 20 is swung back andforth as by link means 22 which is of adjustable length, this link beingpivotally connected at 23 to the lever 20 and at its other end at 24 toa member 25 which may incidentally be a cam member rotated about an axis26 for operating the above-mentioned blockade arrangement.

During the reciprocating movement of the scoop elements 12 and 13, thevertical spacing therebetween is alternately increased and decreased bylinkage means so that the scoop elements enter the bag month while theyare closer together, and will then expand apart or become more separatedto engage the interior surfaces within the mouth of the bag and continuesuch engagement until the bag is pulled over the loaf of bread,whereupon their vertical spacing may be reduced again. With machines ofthe type above referred to, this is accomplished by a cam 27 rotatableon axis 26 and engaging a cam follower 28 mounted on an upstanding lever29 which is pivotally mounted at 29a.

Lever 2? is pivotally connected at 30 to a link member generallyindicated at 31,. the other end of which is pivotally connected at 32 toa bell crank 33 having its central pivot at 21 and having an arm 33apivotally connected at 34 to a link 35. A spring 32:: normally pullsagainst link means 31 and thereby acts to maintain cam follower 28 incontact with cam 27. Link 35 is pivotally connected at 35a to a bellcrank 36 pivotally mounted on an axis at 19. Another arm 36a of thisbell crank is pivotally connected at 37 to a link 38, the latter in turnbeing pivotally connected at 39 to another bell crank 40 having itscentral pivot at 18 and having another arm 40a which is slotted toprovide an adjustable pivotal connection 41 to a further link 42, thelatter in turn being pivotally connected at 43 to a rocker arm 44. Therocker arm 44 is pivotally mounted at 45 and carries at its left-handend 44a the upper scoop element 12.

It will be apparent that the linkage by which the upper scoop element istilted by rotation of cam 27, is such that the tilting movement can beimparted during reciprocation of the shuttle member 16 withoutinterfering with the reciprocating movements of the scoop elements.

The parts of the machine as thus far described, with the exception ofthe construction of the link means 31 as hereinafter explained, may allbe constructed and operated in accordance with the known machines of theabovementioned type. Of course, the various parts are power driven bysuitable mechanical connections as from a motor 46 (FIG. 1) so that eachportion of the machine will operate in proper synchronous relation tothe other portions and the accompanying conveying means.

Referring further to the link 31, in former examples of this machine,this link was simply adjustable in length by reason of its threadedends, and upon such adjustment and possible adjustment of various othersof the links, the scoop element 12 would be tilted up and down asrequired during each stroke and as above explained. Once the linkageswere thus adjusted, although the scoop 12 and its rocker arm support 44amight have some resiliency, yet the limits of the up and down movementsthereof would be substantially fixed and not variable without stoppingthe machine and readjusting the linkage or other parts. However, asexplained in said Chambless application, the desirable upward swingingmovement of this scoop element may vary from bag to bag, so that itshould stop at the level of one or another of the dotted lines, asindicated at 48 (see upper left corner of FIG. 2), and in doing so,apply substantially a predetermined upward pressure against the innersurface of the mouths of bags even if of inaccurately-formed dimensions.To make this possible in accordance with the present invention, the link31 has interposed therein a suitable cylinder and piston means,indicated at 49 with the piston operated by air pressure in a directiontending to pull against the bell crank arm 33. By following through thelinkage shown in FIG. 2, it will be apparent that this pulling effectacts to apply an upward tilting pressure to the scoop rocker arm 44a,but at no time a greater pressure than that corresponding to the airpressure in the device 49, as more fully explained in said Chamblessapplication.

Referring now more particularly to FIG. 3, the upper surface of thelower scoop element is here shown just after it has entered the mouthportions 50 of a bag. A pair of clamping members 51 and 52 are hereshown as clamping such month portions of the bag against the sideportions 13a of the scoop element. The clamping members 51 and 52respectively are carried on lever members 54 and 55 which cross eachother and are pivotally mounted at 56 on the underside of the scoopelement 13. Extended portions of these levers are pivotally attached asat 57 and 58 to push-pull rods 59 and 60 which are arranged to be pulledto bring the clamps into clamping position by a suitable pressure fluidcontaining cylinder and piston device 61 suitably connected to actagainst springs as at 62, 63, which springs normally tend to push therods 59 and 60 in a direction to open the clamps. The connectionsbetween the device 61 and the rods 59 and 60 may for example comprise apiston rod 64 pivotally connected as at 65 to suitable bracket members66 and 67. These in turn have downwardly extending portions pivotallymounted about horizontal axes at 68 and 69. The lower end portions ofthe bracket members 66, 67 are apertured to receive the rods 59 and 60respectively and said springs act between such bracket members and nutsas at 70, 71. Stop nuts as at 72, 73 may be mounted on the rodsrespectively to limit the movement of the bracket means toward the leftas tends to be caused by the springs. Thus when fluid under pressuresuch as air or other fluid is admitted to the device 61 to force aplunger therein toward the left, the pivotal connection at 65 will bepushed to the left thus pushing the lower end portions of the brackets66, 67 against the springs thereby pulling the clamps to their closedpositions, as shown in FIG. 3. When the pressure in the device 61 isreleased, it will be apparent that the springs will tend to push thelower end portions of the brackets 66, 67 to the left, thus pushing theclamps to open position where they will be spaced somewhat from thesides 13a of the scoop element 13. Various other suitable connectionsmay, of course, be devised to permit the clamps to be actuated by thepressure device or even by any other suitable types of devices arrangedand connected to operate in synchronism with the other parts of themachine.

In the example shown, as shown more particularly in FIG. 2, the device61 is connected by an air supply line 75 running to a suitable air valvemeans at 76 which controls the admission and release of air pressure tosuch line from a supply conduit 77. The air valve 76 may be controlledby a suitable cam follower 78 positioned to engage a cam 79. This campreferably has two formations for operating the valve 76, yiz. onerelatively short elevated portion 80 and a considerably longer elevatedportion 81 the length of which may be adjusted by moving a swingable camportion 82 about the axis 26, the portion 82 being held at the desiredposition of adjustment as by screw and slot means shown at 83.

The clamps 51, 52 may preferably be faced by layers of rubber,rubber-like material or possibly foam plastic material, as indicated at53, to facilitate gripping the film of the bag without danger ofrupturing same.

As shown in FIG. 4, the ends of the scoops 12 and 13 are about to enterthe mouth of a bag 50 which has been opened up as by known air jetmeans, this bag coming from the top of a stack thereof indicated at 50a.At this point, as shown in FIG. 4, the clamps 51, 52 are shown in theiropen or retracted positions. Also the upper scoop 12 has not as yetmoved up to engage the upper interior surface of the bag.

As shown in FIG. 5, however, the forward ends of the scoop elements 12and 13 have entered into the mouth of the bag 56, and the upper scoopelement 12 has been raised up into frictional engagement with the upperinterior surface of the bag mouth. Here also the clamps 51, 52 have beenmoved to engage the outer surfaces of the bag mouth and to clamp sameagainst the sides 13a of the scoop 13. This actuation of the clamps iscaused by operation of the air valve 76 through the medium of the camformation 80. The clamps are preferably caused to be closed when thescoops are at positions about one and one-half inches from the end oftheir forward stroke. This closing of the clamps against the bag causespulling of the bag off a conventional wicket therefor without any unduestrain on the side walls of the bag. In FIG. 5 torn apertures areindicated at 50b where the end portion of the bag has been pulled fromthe conventional wicket means.

The clamps 51, 52 upon engaging the sides of the bag mouth may, however,do so at a time when there is some slack in the film of the bag mouth atpoints between the clamps particularly in under the scoop 13. Thus toenable the upper scoop element 51 upon rising into contact with theupper interior surface of the bag mouth to apply tension forstraightening out such slack, the cam formation permits the air valve tooperate and to release the clamps momentarily. After opportunity hasbeen had for thus removing said slack, the cam formation 81 againoperates the air valve to in turn cause reclosing of the clamps. Thisshould occur immediately after the scoops begin their travel on theirretracting stroke. The clamps will then remain closed until the scoopelements draw the bag over the object to be packaged and until theobject contacts with or is about to come into contact with the blockingelement 15, whereupon the clamps release at a predetermined adjustabletime depending upon the angular position of adjustment of the camportion 82 shown in FIG. 2.

The parts are preferably adjusted so that the clamps will open when abag has been pulled completely over an object such as a loaf of bread tothe extent that the heel of the loaf meets the usual bottom gussetportions within the bag. Thus any possibility is eliminated that the bagmay slip off from the scoops when the loaf is only partially in the bag,as well as eliminating the possibility of the loaf being collapsedagainst the blockade due to any excessive drag against the scoops. Inthis way also the problem is avoided which sometimes has occurredheretofore of rupturing the gusset within the bag where in the usualcase there are four thicknesses of the film which come together with theconsequence that sometimes the gusset is not of the desiredpredetermined dimensions.

In view of the operation of the bag clamps, the scoops may be soarranged and operated that the tension which they apply within the bagmouth to the film may be considerably lessened, yet since the clampspermit the bag to be forcefully drawn onto the loaf or other objectaccurately to the desired predetermined extent without slippage from thescoops, it becomes possible to use bags which will more tightly fit theobject being packed without necessarily subsequently subjecting thepackage to any process for shrinking the film of the bag more closelyabout the object.

Although a certain particular embodiment of the invention is hereindisclosed for purposes of explanation, further modifications thereof,after study of this specification, will be apparent to those skilled inthe art to which the invention pertains. Reference should accordingly behad to the appended claims in determining the scope of the invention.

What is claimed and desired to be secured by Letters Patent is: i

In the claims:

1. In a machine for automatically applying bags of sheet material to anobject to be bagged therein, the machine having a pair of opposedscoop-like elements, means for reciprocably mounting same to travel pastthe object to be bagged and to enter into the open mouth of a bag,mechanism being povided to then spread apart said elements and intoengagement with the interior surfaces of the mouth of the bag, saidreciprocable mounting means then acting to retract said elements withthe bag thereon and to pull the bag into surrounding relationship to theobject being bagged, the improvement which comprises providing a pair ofclamping members on at least one of said scoop-like elements forclamping portions of the bag wall adjacent its mouth against saidelement, said clamping members crossing each other and being pivotallymounted together in a scissor-like manner to clamp against oppositesides of said one of the scoop-like elements, and mechanism foroperating said pair of clamping members in timed relation with thereciprocation of said element to actuate said clamping members toclamping position after the scoop elements have entered the bag mouthand for releasing said clamping members after the scoop elements havebeen retracted to pull the bag about said object, said mechanism foroperating the pair of clamping members being connected to actsimultaneously to operate both of said pair in opposite directions withrespect to each other but in directions toward and from the scoopelement on which same are mounted.

2. A machine in accordance with the foregoing claim 1 and in which themechanism for operating the clamping means includes pressure-operatedcylinder and piston means, cam means driven to operate in synchronismwith the operation of the machine, and valve means actuatable by saidcam means to control said cylinder and piston means.

3. A machine in accordance with the foregoing claim 1 and in whichadditional mechanism is provided including air pressure operated meansfor applying a predetermined force acting to cause said scoop elementsto exert a predetermined spreading pressure against the interiorsurfaces of the bag mouths nothwithstanding variations of the latterfrom normal size when spread open.

4. In a machine for automatically applying bags of sheet material to anobject to be bagged therein, the machine having a pair of opposedscoop-like elements, means for reciprocably mounting same to travel pastthe object to be bagged and to enter into the open mouth of a bag,mechanism being provided to then spread apart said elements and intoengagement with the interior surfaces of the mouth of the bag, saidreciprocable mounting means then acting to retract said elements withthe bag thereon and to pull the bag into surrounding relationship to theobject being bagged, the improvement which comprises providing a pair ofclamping means in spaced apart positions on a least one of saidscoop-like elements for clamping portions of the bag wall adjacent itsmouth against said element, and mechanism for operating said clampingmeans in timed relation with the reciprocation of said element toactuate said clamping means to clamping position after the scoopelements have entered the bag mouth and for releasing said clampingmeans after the scoop elements have been retracted to pull the bag aboutsaid object, said clamping means includes pressureoperated cylinder andpiston means, cam means driven to operate in synchronism with theoperation of the machine, valve means actuatable by said cam means tocontrol said cylinder and piston means, said cam means being providedwith at least two valve-operating formations, one for causing actuationof the cylinder and piston means to close the clamping means momentarilyand then open same to allow the scoop elements while being spread apartto tension any slack bag wall portions which are between the clampingmeans, and the other valve-operating formation then acting to againclose the clamping means and retain same closed until the bag is drawnover said object.

5. In a machine for automatically applying bags of sheet material to anobject to be bagged therein, the machine having a pair of opposedscoop-like elements, means for reciprocably mounting same to travel pastthe object to be bagged and-to enter into the open mouth of a bag,mechanism being provided to then spread apart said elements and intoengagement with the interior surfaces of the mouth of the bag, saidreciprocable mounting means then acting to retract said elements withthe bag thereon and to pull the bag into surrounding relationship to theobject being bagged, the improvement which comprises providing clampingmeans on at least one of said scoop like elements for clamping portionsof the bag wall adjacent its mouth against said element, and mechanismfor operating said clamping means in timed relation with thereciprocation of said element to actuate said clamping means to clampingposition after the scoop elements have entered the bag mouth and toclose the clamping means while the bag is being pulled from retainingmeans therefor, then to open said clamping means to permit the scoopelements as they spread apart to straighten out any slack between theclamping means, then to close the clamping means again, and finally toagain release the clamping means after the scoop elements have beenretracted to pull the bag about said object.

References Cited UNITED STATES PATENTS 2,850,855 9/1958 Otfuit 53272,973,610 3/1961 Randall 53188 2,986,858 6/1961 Randall 53190 X3,358,414 12/1967 Hersh et al. 53261 X THERON E. CONDON, PrimaryExaminer.

R. L. SPRUILL, Assistant Examiner.

US. Cl. X.R. 53-261, 384

